Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could celebrate celebrate you could celebrate celebrate he could celebrate celebrate we could celebrate celebrate you could celebrate celebrate they could celebrate celebrate
V-ing form
I could be celebrate celebrating you could be celebrate celebrating he could be celebrate celebrating we could be celebrate celebrating you could be celebrate celebrating they could be celebrate celebrating
Perfect
I could have celebrate celebrated you could have celebrate celebrated he could have celebrate celebrated we could have celebrate celebrated you could have celebrate celebrated they could have celebrate celebrated
V-ing perfect
I could have been celebrate celebrating you could have been celebrate celebrating he could have been celebrate celebrating we could have been celebrate celebrating you could have been celebrate celebrating they could have been celebrate celebrating
Negation
Simple form
I could not celebrate celebrate you could not celebrate celebrate he could not celebrate celebrate we could not celebrate celebrate you could not celebrate celebrate they could not celebrate celebrate
V-ing form
I could not be celebrate celebrating you could not be celebrate celebrating he could not be celebrate celebrating we could not be celebrate celebrating you could not be celebrate celebrating they could not be celebrate celebrating
Perfect
I could not have celebrate celebrated you could not have celebrate celebrated he could not have celebrate celebrated we could not have celebrate celebrated you could not have celebrate celebrated they could not have celebrate celebrated
V-ing perfect
I could not have been celebrate celebrating you could not have been celebrate celebrating he could not have been celebrate celebrating we could not have been celebrate celebrating you could not have been celebrate celebrating they could not have been celebrate celebrating
Interrogative form
Simple form
could I celebrate celebrate? could you celebrate celebrate? could he celebrate celebrate? could we celebrate celebrate? could you celebrate celebrate? could they celebrate celebrate?
V-ing form
could I be celebrate celebrating? could you be celebrate celebrating? could he be celebrate celebrating? could we be celebrate celebrating? could you be celebrate celebrating? could they be celebrate celebrating?
Perfect
could I have celebrate celebrated? could you have celebrate celebrated? could he have celebrate celebrated? could we have celebrate celebrated? could you have celebrate celebrated? could they have celebrate celebrated?
V-ing perfect
could I have been celebrate celebrating? could you have been celebrate celebrating? could he have been celebrate celebrating? could we have been celebrate celebrating? could you have been celebrate celebrating? could they have been celebrate celebrating?
Interro-negative form
Simple form
could I not celebrate celebrate? could you not celebrate celebrate? could he not celebrate celebrate? could we not celebrate celebrate? could you not celebrate celebrate? could they not celebrate celebrate?
V-ing form
could I not be celebrate celebrating? could you not be celebrate celebrating? could he not be celebrate celebrating? could we not be celebrate celebrating? could you not be celebrate celebrating? could they not be celebrate celebrating?
Perfect
could I not have celebrate celebrated? could you not have celebrate celebrated? could he not have celebrate celebrated? could we not have celebrate celebrated? could you not have celebrate celebrated? could they not have celebrate celebrated?
V-ing perfect
could I not have been celebrate celebrating? could you not have been celebrate celebrating? could he not have been celebrate celebrating? could we not have been celebrate celebrating? could you not have been celebrate celebrating? could they not have been celebrate celebrating?